You are tired and fatigued not due to over work. Rather out of Boredom. Boredom is the product of Monotony. Doing the same thing day in day out leads to Boredom.
Escape from this malady by changing your work mode. Change your patterns of work often.A change in work practices will lay roads to enthusiasm and zeal. Get up and direct all your endeavors to flush away boredom from your life in order to enjoy a life of Bliss.